Traditional aeronautical data links are relatively expensive and are becoming more congested. At the same time, the FCC recently auctioned licenses for broadband cellular data services explicitly for use to/from aircraft. The primary intention of this new licensed band is to provide Internet access to aircraft passengers. There are also other broadband services provided to aircraft passengers via SATCOM data links. WiFi (IEEE 802.11) access points at airport gates also provide broadband services to aircraft. These new broadband data links are attractive to airlines for use as cockpit communications data links since they would likely result in lower operating costs for data link services. However, the problem of safety and security of cockpit communications has been a significant technological challenge. The cockpit data communications are required for the safe operation of the aircraft. However, the problem of safety and security of the cockpit communications has been a significant technology challenge, since these cockpit data communications are required for the safe operation of the aircraft.